Reversible depression of spontaneous brain electrical activity induced by actinomycin D and 7-aminoactinomycin D in rats

Summary Various types of actinomycin (C, D, S₂, I and V) and 7-amino-analogue of actinomycin D were injected into the right lateral ventricle of the brain through a chronically implanted cannula. In rats but not in mice actinomycin D, actinomycin S₂ and 7-aminoactinomycin D caused depression of EEG, while cardiac and respiratory activity were maintained. This effect of the EEG was reversible and a normal EEG pattern reappeared at least 3 h after administration.     

Changes of X-prolyl dipeptidyl-aminopeptidase activity in developing rat brain.

We found X-prolyl dipeptidyl-aminopeptidase activity in rat brain and examined the developmental changes at various ages. The total enzyme activity per brain increased until 4 weeks of age, and then decreased during maturation. Specific activity in young rat brain was higher than that in adult rat brain. The properties of the brain enzyme were different from those of pituitary and other tissues.     

Pseudolymphoma of skin induced by oriental hornet (Vespa orientalis) venom.

Intradermal injection of saline suspension of Vespa orientalis venom sac to 57 black mice caused a local nodule composed of lymphocytes, few histiocytes and plasma cells 10 to 12 days following the injection. This reaction simulates the pseudolymphoma reaction observed in humans following arthropode stings.     

Changes of X-prolyl dipeptidyl-aminopeptidase activity in developing rat brain

Summary We found X-prolyl dipeptidyl-aminopeptidase activity in rat brain and examined the developmental changes at various ages. The total enzyme activity per brain increased until 4 weeks of age, and then decreased during maturation. Specific activity in young rat brain was higher than that in adult rat brain. The properties of the brain enzyme were different from those of pituitary and other tissues.     

Changes in IAA oxidase activity in rooting hypocotyl cuttings ofPhaseolus mungo L.

Summary IAA oxidase activity increased concomitant with root initiation during 16–52 h, in all cultures, thus showing the necessity of an active IAA oxidase for root initiation inPhaseolus mungo hypocotyl cuttings. The increase being very sharp in IAA alone, but less in all other cultures. The role of sucrose in root initiation via IAA oxidase activity has been discussed.The research has been partly financed by a grant from the US Department of Agriculture. One of us (R.N.C.) is thankful to the CSIR, India, for financial assistance.     

Effect of experimental allergic encephalomyelitis γ-globulin upon the electrical activity of the brain

Zusammenfassung Die direkte Wirkung eines-Globulin-Präparates aus Kaninchenserum (Injektion in laterale Hirnkammer des Kaninchens) auf die experimentelle allergische Encephylomyelitis wurde dargestellt und elektroencephalographisch eine Inaktivierung verschiedener Hirnregionen festgestellt.     

Pseudolymphoma of skin induced by oriental hornet (Vespa orientalis) venom

Summary Intradermal injection of saline suspension ofVespa orientalis venom sac to 57 black mice caused a local nodule composed o flymphocytes, few histiocytes and plasma cells 10 to 12 days following the injection. This reaction simulates the pseudolymphoma reaction observed in humans following arthropode stings.     

Anticholinesterase-like activity by oriental hornet (Vespa orientalis) venom and venom sac extract.

Oriental hornet venom or venom sac extract produces pharmacological and toxicological effects typical of anticholinesterase agents. The effects produced in animals can be counteracted by atropine and heparin.     

Changes induced by manganese in fish testis

Summary Exposure ofColisa fasciatus, a freshwater teleost, to 2500 mg/l manganese sulphate for 90 h caused decreased spermatogenic activity and hemorrhage in the testes.     

Changes in newt brain caused by zinc water-pollution

Summary The zinc content of various organs of newts kept in zinc-polluted water was estimated by atomic absorption spectrophotometry. Histological examination revealed the presence of zinc-rich, unusual cells in the primordium hippocampi of chronically poisoned animals.     

Changes in the distensibility of the cat aortic arch induced by noradrenaline

Summary In the isolated preparation of the aortic arch of the cat, noradrenaline (NA) reduced at low pre-loads, and increased at high pre-loads, the arterial wall distensibility. For each dose of NA, the changes were directly related to the pressure level in the system.     

Changes in brain acetylcholinesterase activity of young rats after chronic treatment with tremorine

Résumé La trémorine a été administrée chez les rats quotidiennement pendant 7 jours à des doses de 7.5, 22.5 ou 30 mg/kg. Les témoins ont montré des mouvements convulsifs proportionnels à la dose de trémorine. Quatre jours après l'arrêt du traitement, l'activité acétylcholinestérasique du cortex cérébral était augmentée. Il est proposé que ce change de l'activité acétylcholinestérasique reflète une utilisation accrue de l'acétylcholine corticale.

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Acknowledgement: This investigation was supported by a U.S. Public Health Service Grant No. NS 09199 and a Research Scientist Development Award No. K02 MH-42479 from the National Institute of Mental Health, National Institutes of Health.

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The author gratefully acknowledges the technical assistance ofSandra Roland.     

Effects of octylguanidine on the electrical activity of Xenopus heart.

The effects of laboratory synthesized octylguanidine are described. There is an early decease of the maximum rate of rise of the action potential with negligible reduction of the overshoot although the membrane resting potential is unchanged. Subsequently, there is a remarkable reduction of both membrane potential and overshoot, while the plateau is shortened. The former effects resemble those seen with tetrodotoxin, the latter ones, with metabolic poisons.